The dive site Choirboys Reef or Kate's Secret Reef is an offshore rocky reef in the Gordon's Bay area of False Bay, near Cape Town in the Western Cape province of South Africa.
See also: Diving the Cape Peninsula and False Bay#Understand
This site is far enough offshore to be generally outside the eddy of low visibility that often occurs off Gordon's Bay, but is still reasonably close to the launch sites, and has good biodiversity and more rugged topography than most of the close offshore sites of the area. It appears to be a fairly small area and is mostly unexplored.
The name "Choirboys" is derived from the white colonial ascidian of that name which is fairly common at the site.
Maximum depth is about 26 m. and the top of the reef is about 21 m. (Average depth of a dive is likely to be about 23 m.
Visibility is likely to be better than at the Gordon's Bay inshore dives, as it is outside the Gordon's Bay eddy, but is unpredictable. Surface conditions may not accurately predict bottom conditions, particularly in late summer and autumn, after the thermocline develops.
The site is a sloghtly raised area on the ridge which runs out from off Strand to Steenbras Deep. There is a not a lot of variation in depth over the site, and reef profile found has mostly been 2 m or less.The surrounding reef is very flat. The ridges tend to run roughly north-south, following the strike of the strata.
Geology: Probably Pre-Cambrian sedimentary rock of the Tygerberg series. Strike is probably roughly North-South, Dip appears to be steep. The reef is an outcrop of hard rock strata, probably a sandstone.
The site is exposed to winds from all directions, but north-westerlies and south-easterlies will not have enough fetch to develop a substantial wind wave, and wind chop will die down in a few hours. South westerly swell entering the bay will reach this area uninterrupted, and will be the major influence on diving conditions. The site is fairly shallow and surge will be likely in any reasonably long period swell. The site should be dived in low swell, preferably short period, and moderate to light winds.
See also: Diving the Cape Peninsula and False Bay#Boat dives
Usual access: boat dive from Gordon's Bay or Harbour Island. The site is about 10 km from Harbour Island, or (distance)km from Gordon's Bay old harbour.
See also: Diving the Cape Peninsula and False Bay#The marine ecology
The topography is not particularly photogenic, and visibility is not likely to be exceptional, so macro and general close-up wide-angle photos are likely to produce the best results. Artificial lighting is recommended for better colour and clearer photos.
There are no recommended routes. Swim around and explore, or hang out near the shotline and take photos as best suits your style and inclinations at the time.
See also: Diving the Cape Peninsula and False Bay#Stay safe
There are no known site-specific hazards
The site is too deep for entry-level certification, and good buoyancy skills are required to avoid damaging the fragile reef life.
See also: Diving the Cape Peninsula and False Bay#Equipment
No special equipment required, though a light and DSMB are recommended.
Other offshore dive sites of False Bay:
Back to the Alphabetical list of sites, or list of reef dive sites in the northern False Bay offshore area
Other regional dive sites: